Mammalian Differentiation

What is compaction?

• Cell volume is excreted in the zygote to create smaller cells

• zygotic and early embryonic cells undergo mitosis without growth, effectively reducing the size each cell

• increased expression of tight junctions in blastomeres to increase cell cohesion

• Chromosomal condensation in first mitosis of a zygote

How do you polarize a cell?

• Induce a electrochemical gradient

• Induce differential protein expression between faces/regions of the cell

• Create a secondary smaller nucleus within the cell

• Eject a polar body

What is one qualitative difference between the trophectoderm and Inner cell mass?

• TE cells become somatic cells in the fetus' body whereas inner cell mass becomes the placenta and supporting gestational tissues

• TE cells are polar whereas the ICM cells are nonpolar

• TE cells become the offspring's ectoderm while the ICM cells become other internal organ types

• TE cells are maternal cells taht protect the blastocyst during development whereas the ICM cells are of the offspring

What is the difference between mosaic and regulative development?

• Regulative is preprogrammed (i.e thru cytoplasmic factors) while mosaic develops according to its neighbors

• Mosaic is preprogrammed (i.e thru cytoplasmic factors) while regulative develops according to its neighbors

• Regulative development has been shown only to occur in fully mature cell systems and does not play a role in development

• Mosaic development has been shown only to occur in fully mature cell systems and does not play a role in development

The Hypoblast becomes what tissue type?

• Neural

• Placental

• Yolk Sac

• Intestinal

is __ expressed in TE while __ is expressed in ICM

• Nanog; Eomes

• Oct4; CDX2

• Cdx2; Oct4

• TGFIID; Oct4

What is the consequence to the blastocyst if Cdx2 is not expressed?

• It will not develop properly

• There will be OCT4 expression in the TE cells

• Hypertrophy of the ICM tissues

• Hypotrophy of supporting gestational tissues

At what stage of development is the second differentiation event?

• Zygotic

• ICM/TE

• EPI/PE

• First mitosis

Why would it be a good idea to review the feedback loop cycles that were discussed in class?

• Because I need to memorize every promotion and inhibition arrow

• Because these complicated interactions determine how cells differentiate

• Because I need to reproduce the images on the test

• Because I want to mess with my classmates and distribute a slightly doctored image of these interactions